Abstract：
Evidence linking greenness to all-site and site-specific cancers remains limited, and the complex role of air pollution in this pathway is unclear. We aimed to fill these gaps by using a large cohort in southern China. A total of 654,115 individuals were recruited from 2009 to 2015 and followed-up until December 2020. We calculated the normalized difference vegetation index (NDVI) in a 500-m buffer around the participants\' residences to represent the greenness exposure. Cox proportional-hazards models were used to evaluate the impact of greenness on the risk of all-site and site-specific cancer mortality. Additionally, we assessed both the mediation and interaction roles of air pollution (i.e., PM2.5, PM10, and NO2) in the greenness-cancer association through a causal mediation analysis using a four-way decomposition method. Among the 577,643 participants, 10,088 cancer deaths were recorded. We found a 10% (95% CI: 5-16%) reduction in all-site cancer mortality when the NDVI increased from the lowest to the highest quartile. When stratified by cancer type, our estimates suggested 18% (95% CI: 8-27%) and 51% (95% CI: 16-71%) reductions in mortality due to respiratory system cancer and brain and nervous system cancer, respectively. For the above protective effect, a large proportion could be explained by the mediation (all-site cancer: 1.0-27.7%; respiratory system cancer: 1.2-32.3%; brain and nervous system cancer: 3.6-109.1%) and negative interaction (all-site cancer: 2.1-25.7%; respiratory system cancer: 2.0-25.7%; brain and nervous system cancer: not significant) effects of air pollution. We found that particulate matter (i.e., PM2.5 and PM10) had a stronger causal mediation effect (25.0-109.1%) than NO2 (1.0-3.6%), while NO2 had a stronger interaction effect (25.7%) than particulate matter (2.0-2.8%). In summary, greenness was significantly beneficial in reducing the mortality of all-site, respiratory system, and brain and nervous system cancer in southern China, with the impact being modulated and mediated by air pollution.
摘要：
将绿色与全部位和部位特异性癌症联系起来的证据仍然有限，空气污染在这一途径中的复杂作用尚不清楚。我们的目标是通过使用中国南方的大型队列来填补这些空白。从2009年到2015年，总共招募了654,115人，并进行了随访，直到2020年12月。我们计算了参与者住宅周围500米缓冲区中的归一化植被指数（NDVI），以表示绿色暴露。Cox比例风险模型用于评估绿色对所有部位和特定部位癌症死亡率风险的影响。此外,我们评估了空气污染的调解和相互作用作用(即，PM2.5，PM10和NO2）通过使用四向分解方法进行因果中介分析，在绿色-癌症关联中。在577,643名参与者中，记录了10088例癌症死亡。我们发现，当NDVI从最低四分位数增加到最高四分位数时，全位点癌症死亡率降低了10％（95％CI：5-16％）。当按癌症类型分层时，我们的估计表明，由于呼吸系统癌症以及脑和神经系统癌症，死亡率降低了18％（95％CI：8-27％）和51％（95％CI：16-71％），分别。对于上述保护作用，空气污染的中介效应(全部位癌症:1.0-27.7%;呼吸系统癌症:1.2-32.3%;脑和神经系统癌症:3.6-109.1%)和负相互作用效应(全部位癌症:2.1-25.7%;呼吸系统癌症:2.0-25.7%;脑和神经系统癌症:不显著)可以解释很大比例.我们发现颗粒物(即，PM2.5和PM10)比NO2(1.0-3.6%)具有更强的因果中介效应(25.0-109.1%)，而NO2的交互作用(25.7%)强于颗粒物(2.0-2.8%)。总之,绿色显著有利于降低所有站点的死亡率，呼吸系统,中国南方的大脑和神经系统癌症，影响由空气污染调节和调节。
